1st Grade: WHAT HAPPENS WHEN YOU SLEEP_sandbox

WHAT HAPPENS WHEN YOU SLEEP – TEACHER NOTES

Description of this Class for Parents + Caregivers

Description of this Class for Parents + Caregivers — Español

INTRO FOR EDUCATORS

First grade students are ready to expand their understanding of sleep beyond routines and rest. This lesson introduces sleep as an active biological process that supports growth, learning, immune strength, and brain cleaning. It connects sleep to various body systems like the brain, muscles, and immune system, framed in student-friendly language.

Unlike the Kindergarten lesson, SLEEP MATTERS, which centers on feelings and routines, this lesson explores the internal work the body does while we sleep, laying the foundation for later learning in biology and health science. Students will come to see sleep not as "doing nothing" but as a time when their body is toiling in a different way behind the scenes.

This lesson helps students understand how sleep supports specific body systems by helping them visualize what the different parts of the body do while we rest. Because skills-based learning solidifies concepts, students will also practice explaining how sleep connects to growth, memory, and wellness.

Our best advice: use playful metaphors like “brain janitor” or “night shift workers” to make complex processes memorable. Keep the tone curious and celebratory, not lecture-based or guilt-driven. As much as we adults know the value of sleep, we also know that sleep is often a battleground within families. Much of the time this boils down to kids not wanting to miss out on whatever goes on after they go to bed. So have fun with this topic, recognizing that many students will need to integrate the information from lots of different resources in order to be convinced of the value of going to sleep.

If you are looking for more content related to sleep, check out this episode about The 4 Pillars of Health from the This Is So Awkward podcast.

Here are the learning objectives for this lesson:

Identify what the brain, muscles, and immune system do during sleep.
Understand that sleep helps the body grow, remember, and stay well.
Explain why + how sleep is an active process.

Here are the activities that go with this lesson–– you can incorporate them into the teaching (they’re also linked in the corresponding section below) OR use them at the end to reinforce the concepts.

ICE BREAKER

What do you think your body is doing while you’re asleep? Is it working or resting?

Teacher note: List student guesses on the board. Then introduce the idea: Let’s find out what really happens inside while you sleep!

YOUR BRAIN WORKS WHILE YOU SLEEP

Teacher note: You have access to a toolkit with slides should you want them. The slide above illustrates some of the brain’s night shift responsibilities while we’re asleep.

Brains don’t turn off when we’re asleep. Instead, they switch jobs. During sleep, the brain is responsible for clearing clutter, filing away memories, and resetting moods. Research shows that the brain works very hard during sleep, doing things like:

Organizing information like what happened during the day or a newly learned piece of information.
Saving new memories so we can remember what we learned (and tossing the ones we don’t need).
Clearing away waste––the brain uses something called the glymphatic system but you can call it the “brain sweeper” or “brain janitor”.
Resetting our mood so we feel calm and ready for tomorrow.

When we sleep, special fluids wash through our brains to clean out things we don’t need anymore. This keeps our brains sharp!

ACTIVITY: MY BRAIN AT WORK

The “My Brain at Work” activity is designed to reinforce the jobs the brain does while sleeping. Open the PDF linked to the right for directions and materials to lead this activity - My Brain at Work

YOUR BODY REPAIRS AND GROWS AT NIGHT

Sleep is the time when the body repairs, grows, and builds itself stronger. We don’t see it happening, but our cells are hard at work. While you sleep (and only when you sleep):

Muscles relax and repair tiny tears that happen with playing and moving around
Bones stretch and grow—during a growth spurt, you only get taller when you sleep!
Skin heals from cuts + scrapes, and other organs like the nose and lungs can fight viruses + other invaders.

The body releases messengers called hormones. Many of them are released throughout the day + night, but one, called Growth Hormone, comes out during sleep.

The bones can grow longer when growth hormone is around
This happens during sleep
So this is when the body stretches and grows the most

Teacher note: Growth in general––and height in particular––can be a very sensitive subject, even in first grade. There may be kids who have had growth issues, or whose siblings are dealing with slow growth. Someone in your class may be receiving growth hormone as a medicine, or they might know someone who is. There are also kids with sleep issues, who either cannot fall asleep or stay asleep at night––the list of reasons why is long, but regardless of the cause, this can be the source of anxiety if kids hear that you need to sleep well each night in order to grow. The point is to focus on the connection between a regular good night’s sleep and the potential to grow––kids tend to sleep more when they participate in sleep routines rather than fight against them. If you are asked for specifics, it’s entirely reasonable to say: That’s a great question for you to ask your parent when you get home.

SLEEP MAKES YOUR IMMUNE SYSTEM STRONG

Introduce the immune system as the body’s superhero team. At night, your brain and immune system work together to keep you healthy:

Your brain sends out signals to build more “soldier cells” that fight germs.
If a germ is already in your body, sleep helps the immune system find and stop it faster.
When you’re sick, your body needs extra sleep to recover.

Sleep charges-up the body’s superhero (immune) cells so they’re ready to protect.

When we don’t sleep enough, our immune systems slow down––this might cause someone to catch more colds.
When we’re sick, we often want to crawl into bed and go to sleep––that’s the body’s way of saying: I need a supercharge!

ACTIVITY: GERM FIGHTER COMIC STRIP

The “Germ Fighter Comic Strip” activity is designed to play out how their bodies build strong immune systems while they sleep. Open the PDF linked to the right for directions and materials to lead this activity - Germ Fighter Comic Strip

SUMMARY

Sleep isn’t just resting—it’s when your brain, body, and immune system do some of their most important jobs. Every night, your body runs a night shift to help you grow, think, and stay strong.

LET’S TALK ABOUT IT

Ask:

What’s one job your brain or body does while you sleep?
How does kindness help people feel proud of themselves?
What’s something nice you could say to yourself today?